The Toronto Harbour Commission (THC) Building is a six storey building erected in 1917 in Toronto by Alfred Chapman for the locally run Toronto Harbour Commission. It is now home to the Toronto Port Authority, a federal agency. Workers from the Port Authority have nicknamed the six-storey structure "The T" due to the familiar T patterning on the outside of the building – meant to be evocative of "Toronto". Formerly sitting on the waterfront, infill over the years has left the building on dry land and civic expansion has left it dwarfed by nearby buildings.

Since 1953, the THC Building has been rumored to be haunted by the ghost of Thomas Cates, its former janitor, who died of natural causes while working his night shift. He is most often seen in glimpses in the north-western stairwell where he will be sweeping or mopping the floor.

Nearby on Harbour Street is the old Ontario Provincial Police Headquarters at 90 Harbour Street. Residents complained about the Police Headquarters building for years, but in the late 90's cultural opinion shifted, especially because of the early style of the architecture which is not often seen in these parts anymore.